Directional control valves (DCVs) are essential components in hydraulic and pneumatic systems, allowing the control of fluid flow direction and thus controlling the operation of actuators such as cylinders and motors. These valves can be categorized based on the fluid path control into several types:

1. 2-Way Directional Control Valve:

   • Also known as a 2/2-way valve.
   • Controls the flow of fluid between two ports: an inlet and an outlet.
   • Typically used for on/off control of flow in simple hydraulic or pneumatic systems.
   • Common configurations include normally closed (NC) and normally open (NO) valves.

2. 3-Way Directional Control Valve:

   • Also known as a 3/2-way valve.
   • Controls the flow of fluid between three ports: an inlet, an outlet, and an exhaust port.
   • Used for controlling the direction of fluid flow and actuator movement in single-acting cylinders or pneumatic systems.
   • Common configurations include spring-centered, detented, and pilot-operated valves.

3. 4-Way Directional Control Valve:

   • Also known as a 4/3-way valve.
   • Controls the flow of fluid between four ports: two inlets, one outlet, and one exhaust port.
   • Used for controlling the direction of fluid flow and actuator movement in double-acting cylinders or hydraulic systems.
   • Common configurations include closed center, open center, and tandem center valves.

4. 5-Way Directional Control Valve:

   • Also known as a 5/2-way valve.
   • Controls the flow of fluid between five ports: two inlets, two outlets, and one exhaust port.
   • Used for controlling the direction of fluid flow and actuator movement in more complex pneumatic systems.
   • Commonly used for controlling double-acting cylinders with spring return or detent in the center position.

5. 6-Way Directional Control Valve:

   • Also known as a 6/2-way valve.
   • Controls the flow of fluid between six ports: two inlets, two outlets, and two exhaust ports.
   • Used for specialized applications requiring more complex fluid path control, such as switching between multiple actuators or functions in pneumatic systems.

These are the common types of directional control valves based on fluid path control. Each type of valve serves specific purposes and is selected based on the requirements of the hydraulic or pneumatic system, including the number of ports, actuator type, flow direction, and control strategy. Additionally, directional control valves may have various actuation methods, such as manual, mechanical, solenoid, pneumatic, or hydraulic, depending on the application and system requirements.